13401721643 has 2 divisors, whose sum is σ = 13401721644. Its totient is φ = 13401721642.

The previous prime is 13401721637. The next prime is 13401721661. The reversal of 13401721643 is 34612710431.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 13401721643 - 2⁶ = 13401721579 is a prime.

It is a super-2 number, since 2×13401721643² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (13401721943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6700860821 + 6700860822.

It is an arithmetic number, because the mean of its divisors is an integer number (6700860822).

Almost surely, 2^13401721643 is an apocalyptic number.

13401721643 is a deficient number, since it is larger than the sum of its proper divisors (1).

13401721643 is an equidigital number, since it uses as much as digits as its factorization.

13401721643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 32.

The spelling of 13401721643 in words is "thirteen billion, four hundred one million, seven hundred twenty-one thousand, six hundred forty-three".